The present invention relates generally to a magnetic disk device, and more particularly to a flying lead portion structure of a long-tail flexible printed circuit (FPC) integrally molded with a flexure of a head support mechanism.
A magnetic disk device writes and reads data to and from a rotating magnetic disk by allowing a head slider supported by a flexure to float over the rotating magnetic disk. With the aim of improving a recording frequency band, the long-tail wiring system is replacing the so-called short-tail wiring system. The long-tail wiring system is a flexure and a thin-film wiring pattern portion including a connection portion to a main FPC board that are integrally formed. The short-tail wiring system is an electric connection established between a signal line from the head slider and a connection terminal of the main FPC board through a relay FPC.
The long-tail wiring system uses a so called flying lead; that is, the thin film wiring pattern of the connection portion to the connection terminal of the main FPC board is exposed. The connection is soldered or ultrasonically bonded to the connection terminal of the main FPC board.
Japanese Patent Laid open No. 2002 324823 (Pages 3 and 7; FIGS. 4 and 16), hereby incorporated by reference, discloses a technique in which the terminal of a long-tail FPC on a side of a magnetic head element is wire bonded to a magnetic head element, while a flying lead on a side opposite to the magnetic head element is soldered to a main FPC pad in a low oxygen concentration atmosphere.
If the flying lead is disposed to run parallel to the turning shaft of a carriage, it gives the flying lead a wide area for a connection portion to a connection terminal on the main FPC board. This, however, presents a problem that a stacked portion composed of a polyimide layer supporting the flying lead and a thin-film wiring pattern becomes thinner, whereby the strength of the stacked portion is reduced.